• Grip
  • Paddock Rat
  • Offline
  • From: Santa Rosa, Ca
  • Registered: 2014-01-20
  • Posts: 35

Topic: Roll cage question about “non-mandatory “ bars

We had some frame horn damage in a crash at Sonoma. Unibody car. Everything in front of the sway bar mount area and strut tower is bent but “functional”.

I have two questions:

1. Can we add “bay bars” that protrude the firewall and tie the strut towers to the A post and dash bar intersection?

2. Can I rebuild the frame horns and front bumper, ahead of the strut towers,  out of .120 wall DOM?

I understand there is a rule about factory “factory crush structure” so I want o make sure we are good before proceeding. My concern is that the “effectiveness “ has already been reduced. My plan would be to have no DOM ahead of the front edge of the front tires.

3.D.2 OE Crush Structures. Modifications that reduce the size and/or effectiveness of OE crush structures

Any guidance would be greatly appreciated.

  • Registered: 2013-08-12
  • Posts: 563

Re: Roll cage question about “non-mandatory “ bars

My understanding is that #1 is ok, but #2 isn't. Would need to get clarification from HQ to be sure.

  • Grip
  • Paddock Rat
  • Offline
  • From: Santa Rosa, Ca
  • Registered: 2014-01-20
  • Posts: 35

Re: Roll cage question about “non-mandatory “ bars

Thanks. Will do.

  • From: SF Bay Area
  • Registered: 2012-01-06
  • Posts: 721

Re: Roll cage question about “non-mandatory “ bars

Cut frame stubs from a donor and graft onto your car.

Capt. Delinquent Racing
RUST-TITE XR4Ti - '21 ARSE-FREEZE-APALOOZA  I Got Screwed
The One & Only Taurus V8 SHO #31(now moved on to another OG Delinquent)
'17 Vodden the Hell - (No) Hope for the Future Award, '08 AMP Survivor, '08 ARSE-FREEZE-APALOOZA Mega-Cheater
  • From: Cleveland, OH
  • Registered: 2011-09-03
  • Posts: 2,227

Re: Roll cage question about “non-mandatory “ bars

From the same quoted rule.

Non-OE replacement crush structures are not an acceptable substitute;

Gotta go get a donor nose.

Mistake By The Lake Racing (MBTL)
88 Thunderbird "THUNDERBIRDS ARE GO!", Ex Astris, Rubigo / Semper Fracti
A&D: 2014 Sebrings at Sebring (NSF), 2014 NJMP2 Jurassic Park (SpeedyCop), 2012 Summit Point J30 (PiNuts)
2018 Route Sucky-Suck Rally Miata, 2019 World Tour Of Texas 64 Newport

Guildenstern's Website

  • Grip
  • Paddock Rat
  • Offline
  • From: Santa Rosa, Ca
  • Registered: 2014-01-20
  • Posts: 35

Re: Roll cage question about “non-mandatory “ bars

Guildenstern wrote:

From the same quoted rule.

Non-OE replacement crush structures are not an acceptable substitute;

Gotta go get a donor nose.

I didn’t intend on making a cow catcher. I was talking about rebuilding the frame horns out of something non-OEM. It would all be mounted behind the original bumper cover and hood.

  • From: Cleveland, OH
  • Registered: 2011-09-03
  • Posts: 2,227

Re: Roll cage question about “non-mandatory “ bars

I mean, Non-OE means Non-OE.

But definitely see what Pagel says since he's the one who makes the call.

Mistake By The Lake Racing (MBTL)
88 Thunderbird "THUNDERBIRDS ARE GO!", Ex Astris, Rubigo / Semper Fracti
A&D: 2014 Sebrings at Sebring (NSF), 2014 NJMP2 Jurassic Park (SpeedyCop), 2012 Summit Point J30 (PiNuts)
2018 Route Sucky-Suck Rally Miata, 2019 World Tour Of Texas 64 Newport

Guildenstern's Website

  • From: SF Bay Area
  • Registered: 2012-01-06
  • Posts: 721

Re: Roll cage question about “non-mandatory “ bars

Grip wrote:
Guildenstern wrote:

From the same quoted rule.

Non-OE replacement crush structures are not an acceptable substitute;

Gotta go get a donor nose.

I didn’t intend on making a cow catcher. I was talking about rebuilding the frame horns out of something non-OEM. It would all be mounted behind the original bumper cover and hood.

The problem is that your really have no way of ensuring that the crush structure actually crushes when you have an impact.
Sooo, the front of your car has two, fairly stout spears pointed at whatever you are about to impact. That means that the rest of the plastic and sheet metal move aside as the spear-tipped frame impales the driver on the other side of his/hers NASCAR door bars, or manages to catastrophically puncture a fuel tank/cell.

Remember that manufacturers spend millions of dollars on crash testing their designs. I don't really want to be on the receiving end of your steel tubing tipped crap can.

1973 Chevy pickups have a hood that could decapitate the driver in a severe frontal impact.
1974 and later Chevy pickups have a hood that folds like a sheet of paper in a sever frontal impact.a

Regardless, run your plan past John Pagel.

Capt. Delinquent Racing
RUST-TITE XR4Ti - '21 ARSE-FREEZE-APALOOZA  I Got Screwed
The One & Only Taurus V8 SHO #31(now moved on to another OG Delinquent)
'17 Vodden the Hell - (No) Hope for the Future Award, '08 AMP Survivor, '08 ARSE-FREEZE-APALOOZA Mega-Cheater